Improvement in devices for punching metal plates



W. TUCKER. Devices, for Punching M'etal-Plates. N0.I55,.34-7, Q I Patented Se pt.22,1 874..

WITNESSES mmw - INVENTQR UNITED STATES PATENT QFFICE.

WILLIAM TUCKER, OF FISKEDALE, MASSACHUSETTS.

IMPROVEMENT IN DEVICES FOR PUNCHING METAL PLATES.

Specification forming part of Letters Patent No. 155,347, dated September 22, 1874; application filed August 5, 1874.

so as to provide for substituting new cuttingedges for those which are dulled or worn, instead of constantly grinding the end of the punch to keep the edges good.

The present invention relates primarily to the inventors patented saw-gummer, which is the subject-matter of United States Letters Patent No. 136,110, dated February 18, 1873, and of which one distinguishing feature is the employment of a pun'ch which passes freely through the perforation or out form ed thereby, and is discharged with the punching, so as to obviate withdrawing the punch through the plate, said invention relating to the renewal of the length of saw-teeth by punching,

The power required to out very thick tempered steel plates is great, and provision therefor is difficult, because the ratio of the powers required to out different plates is not a direct ratio, but approximates to the ratio of the squares of the depth or thickness of the respective plates; but the punch that is to cut through a plate of No. 6 wire gage has no stronger edge than one which cuts a No. 12 plate, the edges of both being rectangular. Hence, a punch that will stand cutting a certain thickness of plate with sharpening only infrequently, would be ground away much faster when put through plates considerably thicker.

To obviatefrequently grinding the end of the punch, and thereby'using it up, while considerable time is lost in the operation, and at the same time to adapt the punch to present a perfect cutting-edge to the saw-plate every time a cut is made, a disk or washer of tempered steel is applied to the end of the punch concentric therewith, and a quantity of these washers or cutting-disks are provided for use successively. The same are slightly larger in diameter than the punch, and consequently they out large enough apertures to let the punch fall freely through the perforation or recess. The punch thus furnished is adapted to be made cylindrical, and consequently to be manufactured, with its accessories, with superior facility, and to be dropped into its holder or guide-sleeve from the top, so as to facilitate the operation.

In the accompanying drawing, Figure 1 is a side elevation of a metal punch designed for gumming saws, illustrating this invention. Fig. 2 is a plan view of the same. Fig. 3 is a vertical section on the line 3 3, Fig. 1. Fig. 4 is a perspective view of the punch proper. F'g. 5 is a perspective view of a cutting-disk or washer, for application to the punch according to this invention. 4

Referring to the illustrative and practical form of apparatus shown in the drawing, the frame or stock of this punch is composed of a base, a,with a horizontal top adapted to receive a vertical bed-die, D, with a curved arm, b, springing from one side of the base and terminating above the seat of the die in a divided ring, 0, adapted to receive and support a vertical tube, [-1, which constitutes a guide sleeve or holder for a punch, P, within it. The sleeve or holder H has a horizontal flange or fixed collar at its upper end, to rest on the top of the supporting-ring c, and is of sufficient length to bring its lower end to a point immediately above the die D, a space intervening, however, more than sufficient to receive a plate of the maximum thickness for which the punch is adapted. An axial perforation in'the sleeve or holder receives the punch and accuratelyfits the same, so as to support the latter nearly its entire length. Ears e on the supporting-ring c are perforated transversely, and receive a clamp-bolt, f, which crosses the opening in the supportingring and provides for contracting the same around the guide sleeve or holder, so as to secure the latter in position. Difi'erent punches are accompanied by sleeves or holders of uniform external diameter, but each accurately conformed internally to its punch. The punch being in position, a thin washer or cutting-disk, (J, of tempered steel is introduced beneath the same and applied concentrically to its end or face. To provide for securingthis cutting-disk on the end of the punch, the latter is, by preference, constructed with-an axial projection, 19, and the cutting-disks are made annular, so as to fit around said projection, which operates as a gage or guide. The die D is constructed with a downwardly-flaring orifice, d, communicating with a large lateral recess in the base.

In order to provide for driving the punch freely through the out, the cutting-disks or washers are made slightly larger in diameter than the punch, and the latter is thus adapted to be made cylindrical, which provides, fun ther, for introducing the punch into its holder from above without removing the latter. This greatly facilitates the operation.

The advantages of the general mode of punching, apartfrom the employmentof cutting disks or washers, are as fully set forth in Letters Patent No. 136,110, hereinbefore referred to, and the apparatus or implement above described, excepting the cylindrical punch and the cutting disks or washers in the subject-matter in part of said previous Letters Patent.

In lieu of the employment of the central projection p 011 the lower end or face of the punch to gage the cutting disk or washer concentric with itself and with the orifice in the die D,-

the lower end of the holder or sleeve H may be adapted to embrace the disk or washer, or other means may be provided. In either case it may be necessary, in some cases, to loosen and lift the holder or sleeve to facilitate adjusting the disk or washer, but this will involve little trouble, and will occupy only a moment each time.

Owing to the different modes of adjusting the cutting disk or washer above described, it is obvious that the central orifice in the latter is not essential, and the punch, die, and cutting-disk may be adapted to produce perforations or cuts of otherforms than circular or segmental.

A punch, P, with its guide sleeve or holder H, of proper size, having been selected, the saw-plate to be gummed is supported so as to bring the line of teeth over the die D in proper position. The punch is then dropped into the orifice in its sleeve or holder and acutting-disk, G, is interposed between its lower end and the saw-plate so as to be concentric with the punch and the die-orifice. The blow is then given,

and the disk and punch follow the chip or punching through the die into or through the base. The saw-plate is then fed forward a tooth,the punch is again dropped into position, and a cutting-disk applied so as to present a new cutting-edge to the saw-plate. The second blow is then given, and the operation thus proceeds to completion. The cutting-disks can be readily manufactured so as to be perfectly true, sharp, and of the required temper, and their cost is inconsiderable compared with the amount of work they do and the time and labor in other directions which they save. Being discharged with the chip and punch, they are not unlike fixed ammunition for fire-arms,

a different cutter or washer being used each time; but they are unlike in this, that each cutting-disk can be used twice or repeatedly with equal efiect.

Provision, broadly considered, for adapting the punch to drop through the cuts or perforations in the plate is hereby disclaimed as a part of the present invention, in view of the inventors patent of February 18, 1873, which is based primarily on this feature.

The following is claimed as new in this in vention, namely:

1. The cutting disks or washers O, in combination with a punch, P, the same being inter posed between the face of the punch and the plate, to form the cutting-edges of the former and to provide for renewing the same after each cut, in the manner set forth.

2. A cylindrical punch, P, in combination with a cutting-disk or washer, O, of slightly greater diameter applied loosely to its lower ends, so as to be discharged with the chip, to provide for permitting the punch to drop through the cuts or perforations,-and for dropping the punch into its guide sleeve or holder Without removing the latter, as herein set forth.

3. The combination of a punch, P, having an axial projection, 19, on its face and an annular cutting-disk, (1, supported concentrically by said projection to form the cutting-edges of the punch, substantially as herein described.

WILLIAM TUCKER.

Witnesses:

EMORY L. BATES, ARTHUR L. BATES. 

